THE  RELATION  BETWEEN  PHYSICAL  PROPERTIES  AND 
PHYSIOLOGICAL  ACTION  OF  CERTAIN 
LOCAL  ANESTHETICS 

BY 

RUSSELL  LEWIS  JENKINS 
B.  Chem.  University  of  Pittsburgh,  1920 


THESIS 

Submitted  in  Partial  Fulfillment  of  the  Requirements  for  the 

Degree  of 

MASTER  OF  SCIENCE 
IN  CHEMISTRY 

IN 

THE  GRADUATE  SCHOOL 
OF  THE 

UNIVERSITY  OF  ILLINOIS 
1921 


Digitized  by  the  Internet  Archive 
in  2016 


https://archive.org/details/relationbetweenpOOjenk 


UNIVERSITY  OF  ILLINOIS 


THE  GRADUATE  SCHOOL 


May  27 


191 A 


I HEREBY  RECOMMEND  THAT  THE  THESIS  PREPARED  UNDER  MY 

SUPERVISION  RY  RUSSELL  LEY/ IS  JS.UKIUS 

ENTITLED. THE  RELATION  BETWEEN  PHYSICAL.  PR QPEEEIES- AMD 


PHYSIOLOGICAL  ACTION 

BE  ACCEPTED  AS  FULFILLING  THIS  PART  OF  THE  REQUIREMENTS  FOR 


Recommendation  concurred  in* 


Committee 

on 

Final  Examination* 


*Required  for  doctor’s  degree  hut  not  for  master’s 


a ■ 


■ 


■ 


I wish  to  extend  my  sincere 
thanks  to  Professor  Roger  Adams 
for  the  suggestion  of  this  problem 
and  for  the  interest  he  has  shown 
during  the  experimental  work* 


i 


. . 


. 


TABLE  OF  CONTENTS 

I  - INTRODUCTION ♦ *••»•**•**  • 1 

II  - THEORETICAL  PART 2 

III  - EXPERIMENTAL  PART  * * •••••••••!! 

Y -diethyl  amino  propyl  alcohol*  •••••••  H 

Y -diethyl  amino  propyl  p-nitro  benzoate  hydrochloride  • • 11 

y -diethyl  auiino  propyl  p-amino  benzoate  mono-hydrochloride*^ 

Diisopropyl  aniline  14 

Di  isopropyl  amine  ...................  .-15 

Ethylene  oxide 16 

(3  diisopropyl  amino  ethyl  alcohol 17 

(3  diisopropyl  amino  ethyl  p-nitro  benzoate  hydrochloride.  17 

(3  diisopropyl  amino  ethyl  p-amino  benzoate  mono-hydro chlor- 
ide * * 18 

Di-n-propyl  amine  . ..........  l8 

(3  di-n-propyl  amino  ethyl  alcohol  20 

f3  di-n-propyl  amino  ethyl  p-nitro  benzoate  hydrochloride.  20 

(3  di-n-propyl  amino  ethyl  p-amino  benzoate  mono-hydrochlor- 
ide 21 

IV  - SUMMARY  .22 

V  - BIBLIOGRAPHY 24 


THE  RELATION  BETWEEN  PHYSICAL  PROPERTIES  AND  PHYSIO- 
LOGICAL ACTION  OP  CERTAIN  LOCAL  ANESTHETICS. 

I INTRODUCTION. 

While  considerable  investigation  has  been  carried  out  on 
the  relation  between  chemical  constitution  and  physiological 
properties  of  local  anesthetics,  comparatively  little  work:  has 
been  done  on  the  relation  of  physical  properties  to  physiolog- 
ical action. 

Of  the  physical  properties  of  local  anesthetics  lipoid- 
water  distribution  coefficient,  surface  tension  of  solutions, 
effect  on  colloids,  influence  on  electrical  conductivity  of 
lipoids  and  on  the  permeability  of  cell  membrane es,  and  other 
properties,  the  lipoid-water  distribution  coefficient  has  per- 
haps received  the  most  attention.  Upon  the  relation  of  the 
distribution  coefficient  to  anesthetic  activity  is  based  one 
of  the  more  important  theories  of  anesthesia. 

This  investigation  was  undertaken  with  the  view  of  obtain- 
ing comparative  data  covering  the  physical  properties  and  phy- 
siological action  of  a number  of  compounds  of  the  novocaine 


series 


..... 

- 


-2- 


II  THEORETICAL 

Narcosis  and  local  anesthesia  are  so  closely  related  both 
as  to  the  character  of  the  compounds  employed  to  produce  them, 
and  as  to  the  mecnanism  of  their  action  on  the  organism,  that 
theories  which  apply  to  one  are  as  a rule  applicable  to  the 
other. 

( 1 ) 

Overton  amd  Meyer  state  that  all  fat  or  lipoid  soluble 
compounds  have  some  anesthetic  action  and  the  intensity  of  this 

action  is  proportional  to  the  fat-water  distribution  coefficient. 

( 2 \ . 

Traube'  ' connects  the  anesthetic  action  with  tne  “reten- 
tion pressure"  ( Haft d rue M ) of  the  anesthetic  in  water.  The 
osmotic  force  driving  the  substance  into  the  cell  is  inversely 
proportional  to  the  retention  pressure,  and  this  latter  may  be 
measured  by  the  surface  tension  of  the  water  solution.  The 
smaller  the  retention  pressure  the  greater  tne  concentration  of 
the  anesthetic  near  the  cell  wall  and  the  greater  the  tendency 
for  diffusion  into  the  cell.  As  in  the  Overton  and  Meyer  theory, 
this  theory  does  not  go  so  far  as  to  explain  the  actual  action 
of  the  anesthetic  once  it  is  within  tne  cell. 

»» 

There  are  a number  of  other  theories.  Hober  and 
(3) 

Winterstsin  consider  that  the  anesthetic  acts  essentially  at 
the  cell  wall.  The  excitation  of  a cell  is  connected  with  an 
increase  in  permeability  of  the  cell  wall  and  any  substance 
which  will  decrease  the  permeability,  or  which  interferes  with 
rapid  changes  of  permeability  will  lessen  the  irritability  of 
the  cell.  It  has  been  shown  experimentally  that  substances  of 


*■ 

• 

< 

. , 

• 

. 

* . t.  . . 


■ ■ r 

I 


-3- 


the  type  of  local  anesthetics  do  cause  a decrease  in  permeabil- 
ity of  the  cell  membrane. 

The  cell  wall  is  a semi-permeable  membrane.  Winters!  e in'1  3 
holds  the  view  that  in  small  concentrations  an  anesthetic  clogs 
up  the  pores  of  this  membrane,  reducing  the  permeability.  This 
effect  is  entirely  reversible  and  the  anesthetic  may  be  dissolv- 
ed away,  leaving  the  cell  as  it  was  in  the  beginning.  In  larger 
c oncentrat ions,  however,  the  lipoids,  constituting  part  of  the 
cell  wall,  are  dissolved  away,  producing  a large  increase  in 
permeability  and  an  irreversible  effect. 

This  theory  is  supported  at  least  in  part  by  the  work,  of 

M (5)  ‘ 

other  investigators  . Lillie  states  that  any  substance 
which  can  prevent,  rapid  changes  of  permeability  and  of  electri- 
cal polarization  of  the  cell  wall  acts  as  an  anesthetic. 

One  class  of  theories  of  anesthesia  may  be  grouped  under 
the  head  of  aspiiyxiati on  theories.  The  effect  of  cutting  off 
the  oxygen  supply  of  a frog  by  replacing  its  normal  blood  supply 
with  ojygen  free  saline  solution  is  almost  identical  with  that 
produced  by  the  presence  of  anesthetics*  The  asphyxiation 
theories  differ  from  one  another  mainly  in  the  point  of  the 
oxidation  process  at  which  the  anesthetic  is  supposed  to  act. 
Thus  some  authors  consider  tnat  the  anesthetic  forms  some  sort 
of  loose  chemical  union  with  the  cell  material  and  by  taking 
the  place  of  oxygen  retards  or  prevents  oxidation  ^ 6 K Burge^ 7 ) 
of  the  University  of  Illinois  on  the  other  hand  offers  evidence 
to  show  that  the  anesthetic  decreases  the  catalase  content  of 
the  blood  which  results  in  the  slowing  up  of  oxidation. 


' 


a 


f 

* 

V 


. 


... 


' 


• . - . . t . 


. ( - - X _ - 


...  . . 


-4- 


r 8 \ 

j.  Veszr  ’ however  believes  that  narcosis  is  not  essenti- 
ally due  to  a depression  of  oxidation  changes  alone*  Mauy 
authors  consider  that  the  decrease  in  oxidation  is  merely  inci- 

cental  and  is  not  to  be  connected  with  the  cause  of  anesthesia* 

( 9 ) 

E.  Pribram  states  that  the  chemical  constitution  of 

drugs  does  not  suffice  to  explain  their  pharmacodynamic  or  toxic 

properties.  He  considers  that  there  is  a definite  relation 

between  the  highly  anesthetic  properties  of  members  of  the 

cocaine  series  and  the  marked  lowering  of  the  capillary  con- 

(io ) 

stants  of  the  medium  in  which  they  are  dissolved. 

The  toxicity^ 11  ^ of  many  substances  has  been  shown  to  bear 

a definite  relation  to  lipoid-water  distribution  coefficient, 

vapor  tension,  and  other  physical  properties. 

( 12  ) 

J.  Trauoe  states  that  the  chemical  constitution  is  im- 
portant only  in  so  far  as  it  modifies  the  physical  properties, 
especially  the  surface  activity  and  the  many  properties  arising 
therefrom,  such  as  osmosis,  absorption  of  fluids,  adsorption, 
precipitation,  solubilities,  and  others. 

In  view  of  the  fact  that  no  extensive  systematic  study  of 
the  relation  between  physical  properties  and  physiological  ac- 
tion of  local  anesthetics  has  been  made  this  investigation  was 
begun.  The  novocaine  group  was  chosen  and  it  was  planned  to 
prepare  the  two  series: 

RvHCl  0 

/N  -CHa  - CHa  - 0-  6-  CeH4  - HHa 
x 

RsHCl  0 

">W  - CHa  -CHa-CHa-O-C-  CeH4  - HHa 
fr 


• ; . 

V 

' 

V 

»•  % 

•'  i 

. . 

. > . 

sj 

. 

. 

V 1 

w i 

. , * 

v : . : * 

• * 

. - , 

•'  -V 

. • . 

* 

- 

v 

• 

- 


*>  • , 


i • - 


.. 


v , . .. 


f 


- 


' “ 

. : . I 

: ■ • ..  .* 

. . ■ 


V 


V . 


-5- 


where  R is  methyl,  ethyl,  n-propyl,  isopropyl,  n-butyl,  isobutyl, 
n-amyl,  and  isoamyl,  to  determine  the  fat-water  distribution 
coefficient  and  the  water  solution  surface  tension  of  each  com- 
p ound . 

From  such  a series  the  following  information  could  be  ob- 
tained. 

1.  Comparative  data  covering  the  physical  and  physiologi- 
cal properties  of  eacn  compound  of  the  series. 

2.  The  effect  of  increasing  the  length  of  R,  the  effect  of 


the  methods  differing  in  general  in  the  order  in  which  the  var- 
ious intermediates  are  combined. 


forked  chains  in  R,  and  the  effect  of  increasing  the 


number  of  methylene  groups  between  the  oxygen  and  the 


nitrogen  from  two  to  three  on  the  physical  properties. 


and  the  toxicity  and  anesthetic  power  of  the  novocaines 

( 13) 

There  are  several  methods  for  preparing  the  novocaines' 


Thus: 


CICHaCHa OH 
or  ( CHs  )s0 


H Cl  0 

tRa  NCHa  CHa  0-CCeH4N0a 


H Cl  r 0 
RaNCHa  CHa  OCCeH^Ma 


(2  ) R2M 


NOaCeH4COOH — »MaCeH4C00H *M2CeH4C0Cl 


R a NCR  a CH  a 0-C  C e H4  Ms 


-6- 


(3 


N0aCeH4C00Na 
NOa  CeH4C00H— 


BrCHaCHaBr 


■►NOa  CetUCOCl 


0 

RaNCHa CHa 0-CCeH4N03 

H^Cl  l 0 

Ra  NCHa  CHa  O-C-C  efoNHa 


In  this  last  case  the  p-nitrobenzoic  acid  may  be  first  re- 
duced to  p-amino-benz oic  acid  and  the  procedure  carried  out  as 
above  with  the  exception  of  the  final  reduction. 

boil  with 

(4)  RaOT *■  RaNCHaCHa OH  c^OCC^ioT®l * 3  ^ CHa  >3°0CC»H‘H0a 


Ra  1M  CHa  )a  0 OC  C e H4  NHa 
H Cl 

0 

(5  ) RaNCHaCHaOH  + H00CCeH4N0a  > Rail  CHa  CHa  OCCefoJTOa  + HaO 

l 0 

Ra NCHa CHa 0-CCeH4 NHa 
H"C1 


Method  No.  1 was  chosen  for  this  work. 


Secondary  Amines . 

In  the  laboratory  much  difficulty  was  encountered  in  pre^ 
paring  the  secondary  amines  in  a pure  state.  A method  which 
worked  well  for  one  amine  was  found  to  work  indifferently  or 
not  at  all  in  preparing  another. 

(33  ) 

Dimethylamine  was  prepared  readily  by  Mr.  Peet  using  the 
method 

N0CeH4lT(CH3  )a  + NaOH >N0CeH4 ONa  + (CHa  )aNH. 


I 


-7- 


Di-n-propyl  amine  was  also  prepared  quite  readily  in  this  way 

(33) 

with  fair  yields  and  Mr.  Burnett  has  used  the  same  method  for 
the  preparation  of  pure  d-n— butylamine ♦ On  the  other  hand  an 
attempt  to  prepare  diisopropyl  amine  by  this  method  from  diiso- 
propyl aniline  gave  negative  results.  While  tne  diisopropyl 
aniline  was  readily  prepared,  all  attempts  to  nitrosate  this 
compound  were  without  results.  One  of  tne  investigators  had 
also  some  difficulty  in  nitrosating  diisobutyl  aniline. 

When  however  the  diisopropyl  amine  was  prepared  according 

( 14  ) 

to  the  method  of  Hofmann  good  yields  were  obtained,  and  the 
amine  was  easily  purified  by  fractional  distillation,  practical- 
ly all  of  it  beink  secondary  amine  with  but  a trace  of  tertiary 
amine.  One  of  the  investigators  has  used  the  same  method  for 
diisobutyl  amine  with  good  results. 

The  di-n-propyi  amine  could  not  be  readily  made  by  the 
Hofmann  method. Attempts  to  so  prepare  it  gave  considerable  propor 
tions  of  primary  and  tertiary  amines  from  which  it  was  almost  im- 
possible to  separate  the  secondary  by  fractional  distillation. 

Much  importance  is  to  be  attached  to  the  concentrations  of 
the  NaOH  solution  used  in  hydrolyzing  the  p-nitrosodialkylaniline 
In  the  preparation  of  the  higher  di-alkylamines  a 10  per  cent, 
solution  gave  little  more  than  a smell  of  amine.  With  a 2 1/2 
per  cent  solution  of  NaOH  Mr.  Burnett  has  succeeded  in  getting 
a 50  per  cent,  yield  of  pure  di-n-butyl  amine  from  p-nitroso-di- 
n-butylaniline . With  the  p-nitroso-di-n-propyl  aniline  a large 
excess  of  NaOH  was  used,  which  was  dissolved  in  enough  water  to 
make  a 5 per  cent  NaOH  solution  when  the  reaction  was  complete. 


-8- 


Thus  the  hydrolysis  was  begun  in  a solution  somewhat  stronger 
than  5 per  cent  and  completed  in  a 5 P®r  cent  NaOH  solution. 

It  was  found  that  the  nitres o compound  should  be  hydrolyzed 
immediately  after  its  preparation  as  it  apparently  decomposes 
on  standing* 

To  summarize  the  work,  on  the  amines,  it  seems  with  the 
data  at  hand  that  the  straight  chain  secondary  amines  can  be 
more  readily  prepared  by  the  nitrosodialkylaniline  method.  The 
amines  are  pure  and  yields  of  $0  per  cent  or  better  are  obtain- 
able. The  method  used  by  V.  d.  Zande  however  gives  better  re- 
sults in  preparing  diisopropyl  and  diisobutyl  amines. 

DIALKYLAnlUO  ALCOHOLS:-  Two  general  methods  were  used  for 
the  preparation  of  the  dialky lamino  alcohols.  For  the  dialky 1- 
amino  propyl  alcohol  the  secondary  amine  was  condensed  with  equi- 

(10  ) 

molar  quantities  of  trimethylene  chlornydrin  . The  yield 

was  45  to  50  Per  cent  but  the  secondary  amine  was  recovered. 

For  the  dialkylamino  ethyl  alcohols  the  secondary  amines 

( 17  ) 

were  condensed  with  ethylene  oxide  . The  presence  of  some 

water  seems  to  hasten  the  completion  of  tne  reaction.  In  one 
case  diisopropyl  amine  and  ethylene  oxide,  both  dry,  were  heated 
in  a sealed  tube  for  18  hours  at  100°,  at  the  end  of  which  time 
12  per  cent  of  the  amine  had  reacted.  The  experiment  was  repeat- 
ed with  a few  drops  of  water  added.  After  heatixig  in  this  case 

however  for  48  hours  in  a sealed  tube  at  100  , the  reaction  was 

0 ° 

complete,  the  entire  product  boiling  at  187  - 191  » 

( *4  ) 

p-NITROBEHZ OYL  CHLORIDE:  p-nitro-benzoyl  chloride  was  rnade:- 
02NCeH4C00H  + PCIb  H0aCeH4C0Cl  + POCI3  + HC1. 


'• 


l 


V 


. . 


. 


. 

. 

. 

• 

. 

• 

J 


Q_ 

— / 

The  P0C13  and  then  the  OaHCelUCOCl  were,  distilled  off  under 

reduced  pressure.  No  difficulty  from  explosion  was  encountered 

when  the  distilling  flask  was  heated  in  an  oil  hath  whose  temper- 

0 

ature  was  not  allowed  to  rise  above  2j>0  and  when  the  vacuum  was 
kept  under  50  mm*  during  uhe  distillation. 

( 1 e ) 

HYDROCHLORIDE  OE  D IALKYLAMIN OETHYL-p-N ITROBENZ OATE  . The 

reaction:- 

0aNCeH4C0Cl  + HOCHaCHaNRa 

in  benzene  solution  goees  much  more  readily  where  R is  methyl  or 
ethyl  than  when  R is  propyl  or  butyl.  With  the  higher  alkyl- 
amino  alcohols  the  reaction  mixture  must  Qe  heated  on  the  water 
bath  for  some  time  before  the  reaction  is  complete. 

The  esters  are  purified  by  precipitation  from  ethyl  acetate 
or  acetone. 

IRON  REDUCTION:-  The  reduction  of  the  nitro  ester  was  car- 
ried on  by  means  of  iron  and  water,  sufficient  HC1  to  start  the 
reaction  being  furnished  by  that  in  combination  wish  the  nitro 
ester.  At  the  end  of  the  reduction  the  mixture  may  be  made  al- 
kaline and  the  free  amino  ester  extracted  by  ether.  When  deal- 
ing with  small  quantities  of  the  ester,  however,  it  was  found 
that  much  better  results  were  obtained  by  using  tartaric  acid  as 
explained  below  in  the  experimental  part.  By  making  the  tartaric 
acid  extract  alkaline  and  extracting  the  free  reduced  ester  from 
the  water  mixture  larger  yields  were  obtained  than  by  extracting 
the  free  ester  from  the  iron  filings  directly. 

Much  work  is  yet  to  be  done  on  this  problem.  The  remaining 
physical  constants  will  be  reported  later.  The  pharmacological 


. 


i.  . 


i. 


- 


• V - 


• , ! 


-10- 


test  s are  to  be  made  elsewhere  and  will  be  reported  as  soon  as 
the  results  are  available. 

There  is  apparently  little  or  no  relation  between  the 
melting  points  and  molecular  weights  of  the  series.  Column  (A) 
is  the  /3  d ialkyl amino  ethyl  para  amino  benzoate  mono-hydro 
chloride  series.  Column  ( B ) is  the  y dialkylaxaino  propyl 
para  amino  benzoate  mono  hydrochloride  series.  The  alkyl  group® 


indicated  at  the 

left 

of  the  table. 
A 

JB 

Methyl.  . 

. l85-6o(l3) 

- 

Ethyl  . . 

• • 

% 

. 156o(3c) 

164° ( is  ) 

propyl.  . 

. 201.5° 

Isopropyl 

• « 

• 

166. 8°(  195°  )' 13 1 

„ 0(29) 

178—  9 

Butyl  . . 

. 170-2°(29) 
, 0 ( 13  ) 

• 195-6 

104O( 28  ^ 

Isobutyl. 

169°^  29 ^ 

Amyl  . . 

. 122-5<23) 

— 

Isoamyl  . 

• • 

• 

. 154°  ( 1 3 ^ 

, o( 39  ) 

169  - 70 

-11- 


II  EXPERIMENTAL  PART 

( 1 e ) 

y -diethyl  amino  propyl  alcohol 
The  mixture 

37  gr  . (C3H5  )sNH 
48  gr.  C1CH 2 CH2 CH 3 OH 

was  refluxed  for  three  hours  or  until  the  reaction  was  complete. 
At  first  a white  solid  separated  out  which  on  continued  reflux- 
inu  redissolved.  'Wien  the  reaction  was  complete  the  mixture  on 
cooling  became  a dark  red  sticky  mass.  This  vras  dissolved  in 
wa  cer,  made  alkaline  with  NaOH,  and  the  oily  layer  of  y diethyl 
amino  propyl  alcohol  was  separated  and  distilled  under  reduced 
pressure.  The  yields  varied  from  45  to  50  per  cent.  The  di- 
ethyl amine  not  reacted  upon  was  recovered. 

( 18  ) 

y diethyl  amino  propyl  para  nitro  b enz  oat e hydrochloride 

47  gr.  of  p-nitro  benzoyl  chloride  was  dissolved  in  500  cc. 
of  benzene.  To  this  was  added  gradually  with  stirring  a solution 
of  33  gr.  of  y diethyl  amino  propyl  alcohol  in  50  gr.  of  benzene. 
The  mixture  became  quite  warm  and  an  oily  layer  separated  out  at 
the  bottom  of  the  beaker.  This  layer  soon  solidified  and  the 
entire  mixture  became  almost  solid.  In  some  runs  no  oily  layer 
separated  out, the  y -diethyl  amino  propyl  para  nitro  benzoate 
hydrochloride  precipitating  as  a solid  at  onoe. 

The  reaction  mixture  was  warmed  on  a water  bath  for  an  hour 
to  insure  completion  of  the  reaction  and  the  solid  filtered  off. 


-12- 


The  yields  were  94  to  97  per  cent  of  the  theoretical* 

diethvl  amino  propyl  para  amino  benzoate 

The  following  directions  were  followed  with  success :- 
Mix-15  gr.Tdiethyl  amino  propyl  para  nitro  benzoate  hydrochloride 
40  gr.  fine  iron  filings 

in  a small  beaker,  add  just  enough  water  to  make  a thick  paste, 
and  jacket  the  beaker  in  cnipped  ice.  Stir  continually.  If  the 
reaction  does  not  start  in  a few  minutes  warm  tne  oeaker  in  the 
hand.  It  is  rarely  necessary  to  warm  the  oeaxer  on  the  water 
bath.  As  soon  as  the  reaction  starts,  i.e.  as  soon  as  the  mix- 
ture begins  to  heat  up  rapidly,  place  the  beaker  in  the  ice  and 
control  the  temperature  of  the  reaction  mixture  by  additions  of 
small  amounts  of  water  or  chips  of  ice.  Do  not  allow  the  mixture 
to  boil.  When  the  reaction  begins  to  slow  up  remove  the  beaker 
from  the  ice,  add  5 grams  more  of  iron  filings  and  a little  water 
with  continued  stirring.  When  tne  reaction  has  ceased,  warm,  on 
the  water  bath  for  a few  minutes  to  insure  completion  of  the  re- 
action. 

How,  add  enough  tartaric  acid  in  water  solution  to  make  the 
mixture  strongly  acid  and  filter  immediately,  washing  tne  iron 
filings  first  with  water  and  then  with  very  dilute  NaOH  solution. 
Very  little  ot  the  reduced  ester  will  now  be  found  in  the  iron 
filings.  Extract  the  filings  with  ether. 

Make  the  liltrate  alkaline  with  Ha OH;  and  extract  with  ether 
four  times.  Mix  the  extract  from  the  filings  and  from  the  fil- 
trate and  evaporate  off  the  ether. 

The  r diethyl  amino  propyl  para  amino  benzoate  is  a reddish 


-13- 


syrup  which  does  not  crystallize. 

■y  diethvl  amino  propyl  para  amino  toenz oate  mono-nvarochloride 

The  free  y diethyl  amino  propyl  para  amino  benzoate  was 
dissolved  in  100  cc . of  95  per  cent  alcohol  and  made  just  neu- 
tral  to  litmus  with  alcoholic  HC1.  It  was  found  that  the 
yield  of  pure  product  could  be  predicted  with  fair  accuracy  from 
the  quantity  of  alcoholic  HC1  used. 

The  alcohol  was  evaporated  off  under  reduced  pressure  and 
the  y diethyl  amino  propyl  para  amino  benzoate  mono-hydrochlor- 
ide,. which  was  a reddish  crystalline  solid,  was  dissolved  in  the 
least  possible  quantity  of  hot  absolute  alcohol  and  an  equal 
volume  of  ethyl  acetate  added  to  the  hot  solution.  The  ester 
precipitated  out  in  beautiful  sparkling  needles  whicn  were 
slightly  orange  in  color  due  to  impurities.  The  yields  varied 
from  60  to  70  per  cent  of  the  theory,  the  larger  yields  being 
obtained  when  larger  quantities  of  ydiethyl  amino  propyl  para 
nitro  benzoate  hydrochloride  were  reduced.  When  15  grams  of  the 
nitro  ester  was  reduced  the  yields  we re  in  the  neighborhood  of 
60  ye r cent.  When  50  grams  of  nitro  ester  was  reduced  a 70  per 
cen-  yield  of  the  ydiethyl  amino  propyl  para  amino  benzoate  mono- 
hydrochloride was  obtained. 

The  color  can  be  removed  by  precipitation  from  water  but  : 
this  is  very  difficult  due  to  the  extreme  solubility  of  the  com- 
pound in  water.  A small  portion  of  the  compound  was  dissolved  in 
a very  little  water.  Some  of  the  water  was  evaporated  off  under 
reduced  pressure  and  the  solution  allowed  to  cool.  Crystals  sep- 


■ - - . ■ 


• • ~ • 


-14- 


arated  out.  The  mixture  was  centrifuged  and  the  deep  red  mother 
liquor  poured  off.  The  cr2rstals  were  dried  on  a porous  tile  and 
reprecipitated  from  absolute  alcohol  and  ethyl  acetate.  The  color 
was  entirely  removed. 

The  y diethyl  amino  propyl  para  amino  benzoate  mono-hydro- 
, o 

chloride  melts  at  164  corrected. 

■Diisopropyl  aniline 

The  isopropyl  bromide  was  made  by  the  method  of  Kamrn  and 

( 19  ) 

Marvel  for  n-butyl  bromide  with  the  exception  that  no  excess 

H3SCU  was  added  to  the  RBr  alcohol  mixture.  The  yields,  when 
the  excess  H2SO4  was  added,  were  about  66  per  cent.  When  no 
H2SO4  in  excess  was  added,  the  yields  of  isopropyl  bromide  were 
80  - 85  per  cent  of  the  theory. 

150  gr.  aniline 

254  gr . isopropyl  bromide 

were  refluxed  for  32  hours  on  a steam  bath.  On  cooling,  the 
entire  mass  solidified. 

The  mono-isopropyl  aniline  hydrobromiue  was  treated  with 
NaOH  solution  and  the  free  mono-isopropyl  aniline  refluxed  with 
234  gr.  of  isopropyl  bromide  for  46  hours.  At  the  end  of  this 
time  large  clear  crystals  had  separated  out.  The  crystals  were 
filtered  off,  washed  with  isopropyl  bromide,  dissolved  in  water 
and  treated  with  NaOH.  The  diisopropyl  aniline  layer  was  separ- 
ated and  distilled.  The  yield  was  63  grams /coiling  entirely  from 
219.3  to  221°. 

To  test  for  the  purity  of  dialkyl  anilines  a convenient 
method  is  as  follows.  One  cc.  of  the  dialkyl  aniline  is  placed 


-15- 


in  a test  tube  with  a thermometer*  One  cc.  of  acetic  anhydride 
at  the  same  temperature  as  the  dialkyl  aniline  is  then  added, 
the  rise  in  temperature  indicating  roughly  the  amount  of  mono- 
alkyl  aniline.  A 1°  rise  indicates  approximately  1 per  cent  of 
mono-alkyl  aniline. 

The  diisopropyl  aniline  showed  no  rise  of  temperature  with 
acetic  anhydride  and  was  therefore  probably  pure.  Its  specific 
gravity  was  .9165  at  22°  C. 

The  mono-isopropyl  aniline  which  had  not  reacted  was  again 
refluxed  with  an  excess  of  isopropyl  bromide  for  100  hours.  The 
diisopropyl  aniline  hydrobromide  again  separated  out  in  large 
crystals,  some  of  which  were  more  than  half  an  inch  long.  The 
yield  was  60  grams  of  di isopropyl  aniline.  The  work  on  the  di- 
isopropyl aniline.was  discontinued  at  this  point  as  it  was  found 
that  it  could  not  be  readily  iiitrosated  and  could  not  therefore 
be  used  in  the  preparation  of  diisopropyl  amine. 

Pi  .isopropyl  Amine 

kany  attempts  were  made  to  nitrosate  the  diisopropyl  ani- 

( 3 5 ) 

line  without  success 

50  gr.  of  di is  op ropy!  aniline 
100  gr.  cone.  HC1 
400  gr.  HaO 
21.5  gr.  NaNOa 

The  aniline  and  HC1  were  mixed  and  cooled.  The  H2O  in  the 
form  of  ice  was  then  added.  The  mixture  was  stirred  continuous- 
ly and  the  NaWOa  in  water  solution  added  very  slowly,  « A num- 

. _ 00 

oer  of  runs  were  made  using  one-fifth  quantities  ( 1 ) at  -12  -4 


-16- 


(2)  at  20°  - 24°,  (3)  and  two  runs  with  a considerable  excess  of 
HaNOs  at  both  low  and  room  temperatures.  In  some  runs  an  oil  ap- 
peared. In  others  no  oil  appeared  and  the  solution  merely  took 
on  a deep  red  color. 

The  Hofmann  method  was  successfully  used  for  the  preparation 

( 14  ) 

of  diisopropyl  amine 

16 0 gr.  of  16  per  cent  alcoholic  UHs 
116  gr.  isopropyl  bromide 

was  heated  in  sealed  tubes  at  100°  for  39  hours.  A white  solid 
separated  out.  The  mixture  was  neutralized  with  HC1  and  the  al- 
cohol distilled  off.  The  solid  residue  was  dissolved  in  water 
and  Ha OH  added  to  free  the  amines.  The  mixture  must  be  kept  cold 
for  the  free  amines  are  very  volatile.  The  amine  layer  was  sep- 
arated and  after  drying  with  UaQH  was  distilled. 

o o 0 

Yield- 33  grams  boiling  33  to  84  . 

The  33  grams  of  amines  were  then  heated  in  a sealed  tube 

o 

with  74  gr.  of  isopropyl  bromide  at  100  until  the  mass  had  en- 
tirely solidified.  The  solid  was  dissolved  in  water,  treated 
with  HaOH,  and  the  amine  layer  separated.  The  amine  after  drying 
with  HaOH  boiled  entirely  from  82°  to  84  . It  was  therefore  prac*- 
tically  pure  di isopropyl  amine.  The  yield  of  diisopropyl  amine 
was  46  grams , 

( a e ) 

Ethvlene  .Qxldn 

100  grams  of  NaOH  was  dissolved  in  100  grams  of  water  and  the 
solution  heated  in  a distilling  flask.  30  gr.  ethylene  chlor- 
hydrine  was  dropped  in  small  portions  thru  a dropping  funnel  into 


• - .4  * . ..  ... 


- 


-17- 


the  solution,  the  ethylene  oxide  vaper  passed  thru  soda  lime 
tubes  to  dry  it  and  then  condensed  in  an  ice  condenser*  The 
liquid  ethylene  oxide  was  collected  in  thin  walled  tubes  which 
were  sealed  off.  Great  care  must  be  taken  to  prevent  loss  by 
evaporation  while  filling  a tube. 

Yields  were  65  to  70  per  cent  of  the  theory. 

( 37  ) 

ft  diisopropvl  amino  ethyl  ale  ohol 

o 

The  diisopropyl  amine  was  heated  at  100  in  a sealed  tube 
with  a slight  excess  of  ethylene  oxide  and  five  drops  of  water 
for  each  25  grams  of  diisopropyl  amine.  The  heating  was  continu- 
ed for  48  hours.  At  the  end  of  this  time  the  reaction  was  com- 

_ 0 0 

plete  and  the  product  boiled  at  187  - 192  corrected. 

(si) 

f. 3 diisooropvl  amino  ethyl  p-nit^o  benzoate  hydrociiloride 

This  ester  was  prepared  in  the  same  manner  as  the  'Y  diethyl- 
amino  propyl  para  nitro  benzoate  hydrochloride,  using  the  follow- 
ing quantities. 

35  gr.  ft  diisopropyl  amino  ethyl  alcohol 
45  gr.  p-nitro  benzoyl  chloride. 

The  reaction  went  smoothly  but  required  at  least  an  hour’s 
heating  on  the  water  bath  to  insure  completion  of  the  reaction. 

A heavy  oil  invariably  precipitated  out  which  on  stirring  solidi- 
fied. The  ester  is  a cream  colored  solid.  The  yields  were  about 
95  Per  cent  of  theoretical. 

After  two  recrystallizations  from  acetone  the  ft  diisopropyl 

0 

amino  ethyl  para  nitro  benzoate  hydr ochloride  melts  at  162. 3 
corrected. 


-L  * 


* 


* 


* . 


-18- 


/3  diisopropvl  amino  ethyl  para  amino  benzoate  mono-hydrochloride 
The  /3  diisopropyl  amino  ethyl  para  nitro  benzoate  hydro- 
chloride was  reduced  by  the  iron  reduction  method  given  above 
arid  the  monohydr ocnlor ide  made  as  above. 

From  three  runs  the  following  yields  were  obtained 

yield 

(1)  from  15  gr.  nitro  ester  - 9»45  gr.  = 69  per  cent  theory 

( 2 ) " 15  M " >■  ~ 9 • 7 M = 72  H " m 

(3)  " 40  *’  " » -29.0  W = 79.4"  M « 

The  weights  given  are  for  the  dry  /3di isopropyl  amino  ethyl 

para  ainino  benzoate  mono-hydrochloride  precipitated  once  from 
absolute  alcohol  and  ethyl  acetate.  This  ester  appears  as  col- 
orless or  very  slightly  cream  colored  crystals  which  after  two 
recrystallizations  from  absolute  alcohol  melt  at  166.8°  corrected. 
Analysis  Calculated  F ound 

Per  cent  of  nitrogen  9.32  9.44 

Per  cent  of  chlorine  11*79  11. 32 

Di-n-pro  cvl  amine 

The  nitroso  dialkyl  aniline  method  was  used  for  the  prepara- 
tion of  di-n-propyl  amine.  'The  n-propyl  bromide  was  prepared 
from  n-propyl  alcohol  by  the  method  of  Kamm  and  narvel  for  n- 

( 19  ) 

butyl  bromide 

The  di-n-propyl  aniline  'was  prepared  by  the  following  method: 
80  gr.  of  aniline 

2 75  gr.  of  n-propyl  bromide 

was  refluxed  for  one-half  hour.  The  mixture  was  then  refluxed 
for  four  hours  during  which  time  107  grams  of  NaOH  in  concentrated 


-19- 


solution  was  gradually  added.  On  separation  and  distillation  of 

o o 

the  aniline  layer  the  fraction  boiling  239  - 241  was  90  grains. 

The  lower  fractions  were  refluxed  for  two  days  with  an  ex- 
cess of  n-propyl  bromide.  On  distillation  the  fraction  boiling 
259°  - 243°  was  80  grams. 

The  total  yield  of  di-n-propyl  aniline  was  13 0 grains  = 83 
per  cant  of  the  theory. 

The  di-n-propyl  aniline  was  nitrosated  as  follows 
30  gr.  di.  -n-propyl  aniline 
90  gr.  cone.  HC1 
ISO  gr.  HaO 
20.7  gr.  NaiJOa 

The  di-n-propyl  aniline  and  HC1  were  mixed,  cooled,  and  the 
water  in  the  form  of  ice  was  added.  The  beaker  was  jacketed  in 
ice.  The  NaNOa  in  a small  amount  of  water  was  added  in  small 

portions  over  a period  of  twenty  minutes.  The  temperature  was 

o 

carefully  controlled  under  3 C. 

Tne  mixture  first  turned  red,  then  almost  black  and  a heavy 
dark  brown  oil  separated  out.  When  the  NalilOa  had  all  been  added 
the  oil  began  to  solidify  and  the  entire  mass  soon  became  almost 
solid.  The  p-nitroso  di-n-propyl  aniline  was  filtered  off, 
pressed  as  dry  as  possiole  and  immediately  hydrolyzed. 

A solution  of  60  gr.  of  UaOH  in  800  gr.  of  water  was  placed 
in  a 2 liter  flask,  fitted  with  a reflux  condenser  and  heated 
to  boiling.  The  p-nitroso  di-n-propyl  aniline  was  added  in  small 
portions  over  a period  of  an  hour  to  this  solution.  The  mixture 
was  then  refluxed  for  two  hours  longer. 


-20- 


At  the  end  of  this  time  the  flask  was  connected  with  a 
(2s) 

Clark  separator  and  the  di-n- propyl amine  collected.  After 
careful  drying  withUaOH  the  di-n-propyl  amine  was  distilled. 

The  yield  was  17  grams  = £0  per  cent  of  that  theoretically  pos- 
sible from  50  gr.  of  di-n-propyl  aniline. 

Much  care  must  be  taken  in  drying  the  amines  before  deter- 
mining’ a boiling  point  as  a small  trace  of  water  will  considera- 
bly lower  the  boiling  point.  The  amines  are  best  dried  by  plac- 
iiig  a small  stick  o 1 NaOH  in  the  amine  and  allowing  this  to 
stand  for  a da}'  or  two. 

( 2 7 ) 

/3- di-n- propyl  amino  ethvl  alcohol 
The  di-n-propyl  amine  was  heated  in  a sealed  tube  at  100° 
wiuh  a slight  excess  of  ethylene  oxide  and  five  drops  of  water 
for  every  twenty-five  grams  of  di-n-propyl  amine.  The  heating 
was  coiitinued  for  48  hours.  Where  the  amine  was  pure  and  only 
a slight  excess  oi  ethylene  oxide  was  used  the  product  contained 
only  ver}'  small  amounts  of  high  boiling  compounds.  When  on  the 
other  hand  the  di-n-propyl  amine  was  made  by  the  Hofmann  method 
and  the  amine  was  therefore  not  quite  pure  and  this  slightly  im- 
pure di-n-propyl  amine  was  eondeiised  with  ethylene  oxide,  consid- 
erable portions  of  the  product  boiled  higher  than  the  boiling 
point  of  ft  di-n-propyl  amino  ethyl  alcohol. 

Ald-n-propy^  smino  et/nyl  para  nitro  bens  cate  hydrochloride 

The  /3  di-n-propyl  amino  ethyl  alcohol  was  condensed  with  para 
nitro  oezizoyl  chloride  just  as  in  the  preparation  of  ft  diisopropyl 
amino  ethyl  para  nitro  benzoate  Hydrochloride. 


-21- 

The  Z3  di-n-proayl  aiu.no  ethyl  para  nitro  benzoate  hydro- 
chloride is  a cream  colored  solid  which  after  two  precipita- 
tions from  acetone  and  one  from  ethyl  acetate  melts  at  134*5° 
corrected. 


/3di-n-propyl  amino  eth.vl  para  amino  benzoate  mono-hydrochloride 

The  /3di-n-propyl  amino  para  nitro  benzoate  hydrochloride 

was  reduced  by  the  iron  method  and  made  just  neutral  to  litmus 

as  described  above.  The  /3  di-n-pro pyl  amino  ethyl  para  amino 

benzoate  m.ono-hydrochloride,  after  precipitation  from  absolute 

alcohol  and  ethyl  acetate,  appears  as  pale  yellow  crystals.  The 

color  is  not  removed  by  reprecipitation  from  absolute  alcohol. 

After  two  recrystallizations  from  absolute  alcohol  the 
_ o 

ester  melts  at  201.5  corrected. 


-22- 


IV  SUMMARY 

(1)  It  was  planned  to  prepare  the  two  series 

H Cl  0 

(a)  R2NCHaCH2  - 0 - C - CeH4lJH2 

H Cl  0 

(b)  Ra'UCHaCHaCHa  - 0 - C - CeH4lIH3  where 

R is  methyl,  ethyl,  n-propyl,  isopropyl,  n-butyl,  isobutyl, 
n-e.myl,  isoamyl  and  to  determine  the  physical  constants  and  phy- 
siological properties*  Certain  experimental  difficulties  pre- 
vented the  synthesis  of  the  entire  series. 

(2)  A comparison  of  the  melting  points  of  the  members  of 
the  series  is  made. 

(3)  The  most  difficult  part  of  the  synthesis  was  the  prepar- 
ation of  the  pure  secondary  amines. 

The  Hofmann  method  as  modified  by  Van  der  Zande  was  found 
best  for  the  preparation  of  diisopropyl  and  diisobutyl  amines- 

For  di-n-propyl,  di-n-butyl,  and  dimethyl  amines  the  p- 
nitroso  dialkyl  aniline  method  was  found  best.  The  concentration 
of  the  alkali  used  in  hydrolyzing  the  p-nitroso  dialkyl  aniline 
is  of  great  importance. 

(4)  Diisopropyl  aniline  can  not  oe  nitrosated  by  the  usual 
me  th  od  s . 

(5)  Methods  for  preparing  /3  di alkyl  amino  ethyl  alcohols 
and  y dialkyl  amino  propyl  alcohols  are  worked  out. 

(6)  A method  for  the  reduction  of  the  nitro  esters  is  worked 


out 


-23- 


(7)  The  dialkyl  amino  propyl  para  amino  benzoate  mono-hydro- 
chloride  can  he  precipitated  as  pure  white  crystals  from  water, 

(8)  Ihe  research  will  be  continued  and  more  physical  con- 
stants determined. 

(9)  The  pharmacological  tests  are  to  be  made  elsewhere  and 
will  be  reported  as  soon  as  available  . 


' 


. 


-24- 


(1) 

(2) 

(3) 

(4) 

(5) 

(6) 

(7  ) 
(8) 

(9) 
(10) 
(11) 
(12) 
(13  ) 


(14) 
(13  ) 
(16) 

(17) 

(18) 
(19) 


V BIBLIOGRAPHY 

Overton  - "Studien  ttber  die  Narkose  zugleich  ein  Beitrag 
zur  allgemainen  PharmacologieM . 

Traube  - Archiv  ges.  Physiol,  176,  7 0;  13  3,  276;  JJS_0,  301, 

Wint  erst  ein  - Deutch  Med,  Woch.  42,  347 

Biochem.  Z.  £Q>  130:  25.*  47 
Archiv.  ges.  Phys.  132 . 31;  153,  276. 

S.  Lowe  - Biochem.  Z.  161* 

Lillie  - Science  XL*  764,  939* 

Verworn  - M Irritability" 

Burge,  Neill  and  Ashman  - Am.  J.  Physiol..  4^.,  388* 

J.  Veszi  - PfliUger’s  Archiv.  1913,  170.  312* 

Pribram  — Verb.  Morphol-physiol.  Ges,  Wien..  June  23,  1918. 

Comptes  Rendu  - 170.  1409. 

J.  Biol.  chem.T  41,  Ho.  3,  XXXVII. 

Traube  - Biochem.  Z.  ^8,  177. 

E inhorn  - Annalen,.  m,  131. 

German  Patents : - 

179627  172368 

180291  189333 

180292  194365 

194748 

Van  der  Zande  - Receuil,  £,  2 05 

Hickenbottom  - Journ.  of  the  Chem.  Soc.  Trans.  1918.  107. 
Ladenburg-  B.  ^4,  2408. 

Khorr  and  Mat the s B-J4,  3484 

Kamm  - J.  Amer . Chem.  Soc.,  ^2.,  1030(1920) 

Kamm  and  Marvel  - J.  Amer.  Chem.  Soc.,  42,  No.  2 (1920  ) 


-25- 


(20)  Zander  - Annalen,  214. 149 : 170 

(21)  Einhorn  - Annalen  371,  140 

(22)  Peet  - Thesis,  Univ.  of  111.,  1921 

(25)  Burnett  - Thesis,  Univ.  of  111.,  1921. 

(24)  Frankland  - J.  Chem.  Soc.  Trans,  18*?. IS 76 

(25)  Mendl  - Monatshefte,  99* 

(26)  Y/urtz  - Annalen,  110.  125 . 

(27)  Matthes  - Annalen,  516.  512. 

(28)  H.  T.  Clarke  - J.  Amer.  Chem.  Soc.,  45 . 566. 

(29)  Adams  - Chem.  Abstracts,  !£.,  412. 

(30)  Httger  - Chemisc^ies  Cent ralhlatt,  1905  (2)  1817. 


